I took this in the summer of 1957 when Nikita Khrushchev, then first secretary of the Communist party of the Soviet Union, visited Berlin. It's taken in the eastern district of Friedrichshain, once in the Soviet sector of the city, and people were excited to see Khrushchev in the flesh.

Nothing about this shot is set up. The two men were sitting on the fence posts when I walked by, and the older man and young woman were exactly as they are in the picture. I didn't ask them to move left a bit or right a bit – I never interfered.

In my work I am particularly interested in the relationships people have to each other, and I think you can see it in this shot. I liked the composition, the way the two men up high were calling out to one another. I didn't know who they were or whether they knew each other. I didn't ask. Back then I never asked anyone's permission before taking a photograph; they probably didn't even realise I was doing it.

I wasn't a professional photographer then: I was a teacher at an art college in Berlin. But whenever I had time, I would travel around the city with my camera. Although Berlin had been divided since 1945, in 1957 you could still travel freely between east and west, and I took pictures on both sides. When this was taken, people had adjusted to the idea of a divided Germany but they never dreamed anyone would build a wall.

This picture belongs to a series called Situation Berlin. It was supposed to go in a book of 40 photos taken in the city between 1956 and 1960. I stopped taking photos of Berlin once the wall went up in 1961 – it didn't interest me any more. I started doing a lot of fashion photography and embarked on a lifelong personal project to photograph every object at my house in Gransee, Brandenburg, with a Polaroid camera.

The book never came out. Just before it was due to be published, an official from the party saw it at a book fair in Leipzig. He said: "Berlin ist kein Situation mehr" ("Berlin is no longer a situation"), meaning that the problem of east Germans fleeing to the west was no longer an issue. With those words my book died. It took until the year 2000 for it to be published.

CV

Born: Berlin, 1927.

Inspirations and influences: Edward Steichen, Robert Frank.

High point: "Shooting Marlene Dietrich on stage in Moscow. She said they were her favourite pictures of her."